CN114063361A

CN114063361A - Color filter array for reflective display device

Info

Publication number: CN114063361A
Application number: CN202110670226.2A
Authority: CN
Inventors: 法兰契·伊恩; 鍾宪腾; 骆伯远
Original assignee: E Ink Holdings Inc
Current assignee: E Ink Holdings Inc
Priority date: 2020-07-29
Filing date: 2021-06-17
Publication date: 2022-02-18
Also published as: US20220035084A1; TW202204997A

Abstract

A color filter array for a reflective display device comprises a plurality of first filter arrays, a plurality of second filter arrays and a plurality of third filter arrays. Each first filter array has a plurality of first filter patterns separated from each other. Each of the second filter arrays has a plurality of second filter patterns separated from each other. Each of the third filter arrays has a plurality of third filter patterns separated from each other. Each first filter array is adjacent to one of the second filter arrays and one of the third filter arrays. The color filter array can effectively reduce the granular sensation of the image displayed by the display device comprising the color filter array.

Description

Color filter array for reflective display device

Technical Field

The invention relates to a color filter array for a reflective display device.

Background

In the market of various consumer electronic products nowadays, reflective electrophoretic display devices are widely used as display screens. The display medium layer of the reflective electrophoretic display device is mainly composed of electrophoretic liquid, and white particles and black particles doped in the electrophoretic liquid. By applying voltage to the display medium layer, the white particles and the black particles can be driven to move, so that each pixel can display black, white or gray scale. The reflecting electrophoresis display device utilizes incident light to irradiate the display medium layer to form reflecting light to achieve the purpose of displaying, so that no backlight source is needed, and the power consumption can be saved. The incident light may be sunlight or indoor ambient light.

In the reflective color electrophoretic display device, a Color Filter Array (CFA) is attached to a display medium layer. However, the grain sense of the image displayed by the current reflective color electrophoretic display device is obvious, and how to reduce the grain sense of the image becomes an urgent issue to be solved in the field.

Disclosure of Invention

To solve the above problems, the present invention provides a color filter array for a reflective display device, comprising: the display device comprises a color filter array with a plurality of filter patterns separated from each other or a plurality of filter units arranged in a staggered manner, so that the graininess of an image displayed by the display device comprising the color filter array is effectively reduced.

The invention provides a color filter array for a reflective display device, which comprises a plurality of first filter arrays, a plurality of second filter arrays and a plurality of third filter arrays. Each first filter array has a plurality of first filter patterns separated from each other. Each of the second filter arrays has a plurality of second filter patterns separated from each other. Each of the third filter arrays has a plurality of third filter patterns separated from each other. Each first filter array is adjacent to one of the second filter arrays and one of the third filter arrays.

According to some embodiments of the present invention, each of the first filter arrays, each of the second filter arrays, and each of the third filter arrays is rectangular in a top view.

According to some embodiments of the present invention, each of the first filter arrays is adjacent to and substantially aligned with one of the second filter arrays and one of the third filter arrays along a length direction thereof, and each of the first filter arrays is adjacent to and substantially aligned with the other of the second filter arrays and the other of the third filter arrays along a width direction thereof.

According to some embodiments of the present invention, each of the first filter arrays is arranged in a staggered manner along a width direction or a length direction thereof with the one of the second filter arrays and the one of the third filter arrays.

According to some embodiments of the invention, a ratio of a length to a width of each of the first filter arrays is between 1.8: 1 and 5: 1.

According to some embodiments of the present invention, a ratio of a width of each first filter array to a width of each first filter pattern is between 2: 1 and 5: 1.

According to some embodiments of the present invention, a ratio of a width of each first filter pattern to a pitch of two adjacent first filter patterns is between 1: 1 and 3: 1.

The present invention further provides a color filter array for a reflective display device, which includes a plurality of first filter units, a plurality of second filter units, and a plurality of third filter units. Each first light filtering unit is adjacent to one of the second light filtering units and one of the third light filtering units along a first direction, one of the first light filtering units is adjacent to the other of the second light filtering units and the other of the third light filtering units along a second direction and is arranged in a staggered mode, and the first direction is perpendicular to the second direction.

According to some embodiments of the present invention, each of the first filtering units, each of the second filtering units, and each of the third filtering units are rectangular at the upward viewing angle.

According to some embodiments of the present invention, the first direction is a length direction of each of the first filter units, and the second direction is a width direction of each of the first filter units.

According to some embodiments of the present invention, a projection of the first filtering unit along the second direction partially overlaps with the other one of the second filtering units.

According to some embodiments of the present invention, an edge of the first filtering unit and an edge of the other of the third filtering units are aligned with each other along the second direction.

According to some embodiments of the present invention, a ratio of a width of each first filtering unit to a length of each first filtering unit is greater than or equal to 1/3.

Drawings

In order to make the aforementioned and other objects, features, and advantages of the present invention comprehensible, embodiments thereof, reference is made to the following detailed description taken in conjunction with the accompanying drawings, in which:

FIG. 1 is a schematic top view of a color filter array according to an embodiment of the invention;

FIG. 2 is an image of a display device employing a color filter array composed of a plurality of solid filter patterns;

FIG. 3 is an image of a display device employing the color filter array of FIG. 1;

FIG. 4 is an enlarged schematic view of the first filter array of FIG. 1;

FIG. 5 is a schematic top view of a color filter array according to an embodiment of the invention;

FIG. 6 is a schematic top view of a color filter array according to an embodiment of the invention;

FIG. 7 is a schematic top view of a color filter array according to an embodiment of the invention;

FIG. 8 is an image of a display device employing a color filter array composed of a plurality of solid filter patterns;

FIG. 9 is an image of a display device employing the color filter array of FIG. 7;

FIG. 10 is a schematic top view illustrating a color filter array according to an embodiment of the invention.

[ notation ] to show

10. 20 color filter array

110 first light filtering array

110a first filter pattern

120. 1202, 1204 second Filter array

120a second filter pattern

130. 1302, 1304 third Filter array

130a third Filter Pattern

210 first light filtering unit

220. 2202, 2204 second filter unit

230. 2302, 2304 third light filtering unit

D1 first direction

D2 second direction

L is the length direction

L1, L2 Length

OL overlap length

OW overlap width

S1, S2, S3 distance

W is the width direction

W1, W1, W2 Width

Detailed Description

The following provides many different embodiments or examples of the invention to achieve different technical features of the provided subject matter. The elements and design of the following specific examples serve to simplify the present invention. These are, of course, merely examples and are not intended to be limiting. For example, the description discloses forming a first feature over a second feature, including embodiments in which the first feature and the second feature are formed in direct contact, and also including embodiments in which additional features are formed between the first feature and the second feature, i.e., the first feature and the second feature are not in direct contact. Moreover, repeated reference symbols and/or verbs may be used in various examples. These repeated symbols or words are provided for simplicity and clarity and are not intended to limit the relationship between the various embodiments and/or the described structures.

Furthermore, spatially relative terms, such as "lower," "upper," and the like, are used for convenience in describing the relative relationship of one element or feature to another element or feature in the figures. These spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. The device may be otherwise oriented (e.g., rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly.

To solve the above problems, the present invention provides a color filter array for a reflective display device, comprising: the display device comprises a color filter array with a plurality of filter patterns separated from each other or a plurality of filter units arranged in a staggered manner, so that the graininess of an image displayed by the display device comprising the color filter array is effectively reduced. In some embodiments, the reflective display device includes the color filter array of the present invention (see fig. 1, 5, 6, 7 and 10), an array substrate (not shown), and a display medium layer (not shown) disposed between the color filter array and the array substrate. The display medium layer can reflect the incident light, so that a user can see the picture displayed by the display device. In some embodiments, the display medium layer comprises microcapsules or microcups. Various embodiments of the color filter array of the present invention will be described in detail below.

Fig. 1 is a schematic top view illustrating a color filter array 10 according to an embodiment of the invention. As shown in fig. 1, the color filter array 10 includes a plurality of first filter arrays 110, a plurality of second filter arrays 120, and a plurality of third filter arrays 130. The first filter array 110, the second filter array 120 and the third filter array 130 are filter arrays of different colors. In some embodiments, the first filter array 110 is a red filter array, the second filter array 120 is a green filter array, and the third filter array 130 is a blue filter array, but is not limited thereto.

Each of the first filter arrays 110 has a plurality of first filter patterns 110a separated from each other. Each of the second filter arrays 120 has a plurality of second filter patterns 120a separated from each other. Each of the third filter arrays 130 has a plurality of third filter patterns 130a separated from each other. Therefore, the color reflectivity (color reflectivity) and the brightness of the display device can be obviously improved, so as to effectively reduce the granular sensation of the image.

Fig. 2 is an image of a display device employing a color filter array composed of a plurality of solid filter patterns. In detail, fig. 2 shows a color filter array formed by general solid filter patterns (not shown), and although the size and color of the color filter array are the same as those of the first filter array 110, the second filter array 120 and the third filter array 130 of fig. 1, the white state reflectivity (white state reflectivity) of the display device formed by the color filter array formed by the solid filter patterns is 18%. As shown in fig. 2, the graininess of the image was quite noticeable.

Fig. 3 is an image of a display device using the color filter array of fig. 1. The white state reflectivity of the display device using the first filter array 110, the second filter array 120 and the third filter array 130 of fig. 1 is 26%. As shown in fig. 3, the graininess of the image was low. Therefore, the first, second and

third filter arrays

110, 120 and 130 of the present invention are helpful to improve the graininess of the image of the display device.

With continued reference to FIG. 1, each of the first filter arrays 110 is adjacent to one 1202 of the second filter arrays 120 and one 1302 of the third filter arrays 130. In some embodiments, each of the first filter array 110, each of the second filter array 120, and each of the third filter array 130 are rectangular at the top viewing angle. In some embodiments, as shown in FIG. 1, each first filter array 110 is adjacent to and substantially aligned with the one 1202 of the second filter arrays 120 and the one 1302 of the third filter arrays 130 along the length direction L, and each first filter array 110 is adjacent to and substantially aligned with the other 1204 of the second filter arrays 120 and the other 1304 of the third filter arrays 130 along the width direction W. In this specification, the term "substantially aligned" means that adjacent two elements overlap or nearly overlap in a projection along a certain direction (e.g., the length direction L or the width direction W).

Fig. 4 is an enlarged schematic diagram of the first filter array 110 of fig. 1. The following disclosure regarding the dimension relationship of the first filter array 110 is also applicable to the second filter array 120 and the third filter array 130 shown in fig. 1. In some embodiments, as shown in FIG. 4, the ratio of the length L1 to the width W1 of the first filter array 110 is between 1.8: 1 and 5: 1. In some embodiments, length L1 is between 200 and 260 microns and width W1 is between 50 and 110 microns.

In some embodiments, as shown in fig. 4, the ratio of the width W1 of each first filter array 110 to the width W1 of each first filter pattern 110a is between 2: 1 and 5: 1. In some embodiments, width w1 is between 15 microns and 40 microns, such as 20 microns, 25 microns, 30 microns, or 35 microns.

In some embodiments, as shown in fig. 4, the ratio of the width w1 of each first filter pattern 110a to the spacing S1 of two adjacent first filter patterns 110a is between 1: 1 and 3: 1. In some embodiments, spacing S1 is between 5 and 30 microns.

In some embodiments, the first filter pattern 110a has an oval shape, but in other embodiments, the first filter pattern may have other shapes, such as a circle or a polygon, for example, a square or a rectangle.

Fig. 5 is a schematic top view of the color filter array 10 according to an embodiment of the invention. The embodiment of fig. 5 is different from the embodiment of fig. 1 in that each first filter array 110 is arranged in a staggered manner along the width direction W with one 1202 of the second filter arrays 120 and one 1302 of the third filter arrays 130.

Fig. 6 is a schematic top view of the color filter array 10 according to an embodiment of the invention. The embodiment of fig. 6 is different from the embodiment of fig. 1 in that each of the first filter arrays 110 is arranged in a staggered manner along the length direction L with one 1202 of the second filter arrays 120 and one 1302 of the third filter arrays 130.

In the present specification, the term "staggered arrangement" means that projections of two adjacent elements in a certain direction (for example, the width direction W or the length direction L) are partially overlapped, or edges of two elements are cut off from each other in a certain direction.

Fig. 7 is a schematic top view of the color filter array 20 according to an embodiment of the invention. As shown in fig. 7, the color filter array 20 includes a plurality of first filter units 210, a plurality of second filter units 220, and a plurality of third filter units 230.

In detail, each of the first filter units 210 is adjacent to one 2202 of the second filter units 220 and one 2302 of the third filter units 230 along the first direction D1, and one of the first filter units 210 is adjacent to and staggered with the other 2204 of the second filter units 220 and the other 2304 of the third filter units 230 along the second direction D2 (the second direction D2 is perpendicular to the first direction D1). In this specification, the term "staggered arrangement" means that the projections of two adjacent elements in a certain direction partially overlap, or the edges of two elements are aligned with each other in a certain direction. In this way, horizontal light (i.e., light along the second direction D2) is facilitated to pass through the gaps between the first, second and

third filtering units

210, 220 and 230, so that the light is prevented from being confined in a specific area, and the graininess of the image displayed by the display device can be effectively reduced.

Fig. 8 is an image of a display device employing a color filter array composed of a plurality of solid filter patterns. Fig. 8 shows a color filter array (not shown) formed by a plurality of solid filter patterns, which has the same size and color as the first filter array 110, the second filter array 120 and the third filter array 130 of fig. 1, but as shown in fig. 8, the image displayed by the display device formed by the color filter array formed by the solid filter patterns has a distinct granular sensation.

Fig. 9 is an image of a display device employing the color filter array of fig. 7. As shown in fig. 9, the image displayed on the display device using the first, second, and

third filtering units

210, 220, and 230 shown in fig. 7 has a significantly reduced graininess. Therefore, the first, second and

third filter units

210, 220 and 230 arranged in a staggered manner according to the present invention are helpful to improve the granular sensation of the image displayed by the display device.

Referring to fig. 7, in some embodiments, each of the first filter units 210 is adjacent to and substantially aligned with the second filter unit 2202 and the third filter unit 2302 along the first direction D1.

In some embodiments, each of the first filtering units 210, each of the second filtering units 220, and each of the third filtering units 230 are rectangular in a top view. In some embodiments, the first direction D1 is a length direction of each first filter unit 210, and the second direction D2 is a width direction of each first filter unit 210. In some embodiments, the length L2 of each first filtering unit 110 is between 100 microns and 150 microns. In some embodiments, width W2 of each first filtering unit 210 is between 30 microns and 55 microns. In some embodiments, the ratio of width W2 to length L2 is greater than or equal to 1/3. The above and following disclosures regarding the size relationship of the first filter unit 110 are also applicable to the second filter unit 220 and the third filter unit 230 shown in fig. 7. In some embodiments, a filter element having a W2/L2 ratio of greater than or equal to 1/3 (e.g., first filter element 210, second filter element 220, or third filter element 230) does not break or generate air bubbles after the reliability test.

In some embodiments, the edges of first filter cell 210 and the edges of third filter cell 2304 are aligned with each other along second direction D2 (i.e., the width direction).

In some embodiments, the projection of the first filtering unit 210 along the second direction D2 (i.e. the width direction) partially overlaps with the second filtering unit 2204, and the overlap length OL is less than the length L2 of each first filtering unit 110. In some embodiments, the overlap length OL is between 5 microns and 80 microns, such as 10 microns, 15 microns, 20 microns, 25 microns, 30 microns, 35 microns, 40 microns, 45 microns, 50 microns, 55 microns, 60 microns, 65 microns, 70 microns, or 75 microns. In some embodiments, the ratio of length L2 to overlap length OL is between 1.3: 1 and 30: 1.

In some embodiments, overlap length OL is less than or equal to spacing S2 of first filter cell 210 from adjacent second filter cell 2202. In some embodiments, overlap length OL is between 5 and 50 microns and spacing S2 is between 30 and 50 microns.

In some embodiments, the spacing S2 is greater than or equal to the spacing S3 between the first filter cell 210 and the adjacent second filter cell 2204. In some embodiments, spacing S3 is between 25 and 45 microns.

FIG. 10 is a schematic top view illustrating a color filter array according to an embodiment of the invention. The embodiment of fig. 10 is different from the embodiment of fig. 7 in that the first direction D1 is a width direction of each first filter unit 210, and the second direction D2 is a length direction of each first filter unit 210. Each of the first filter units 210 is disposed along the second direction D2 (i.e., the length direction) and is staggered with one 2204 of the second filter units 220 and one 2304 of the third filter units 230. In this way, it is helpful for the longitudinal light (i.e. the light along the second direction D2) to pass through the gaps between the first, second and

third filtering units

210, 220 and 230, so as to prevent the light from being confined in a specific area, and thus effectively reduce the graininess of the image displayed by the display device.

In some embodiments, as shown in fig. 10, a projection of first filter unit 210 along second direction D2 (i.e., the length direction) partially overlaps second filter unit 2204 with an overlap width OW therebetween. In some embodiments, the overlap width OW is between 5 and 45 microns. In some embodiments, the ratio of the width W2 of the first filter unit 210 to the overlap width OW is between 1.3: 1 and 30: 1.

The foregoing briefly describes the features of various embodiments and aspects of the present invention so that those skilled in the art may better understand them. Those skilled in the art should appreciate that they may readily use the present invention as a basis for designing or modifying other processes and structures for carrying out the same purposes and/or achieving the same advantages of the embodiments introduced herein. Those skilled in the art should also realize that such equivalent constructions do not depart from the spirit and scope of the present disclosure, and that they may make various changes, substitutions, and alterations herein without departing from the spirit and scope of the present disclosure.

Claims

1. A color filter array for a reflective display device, comprising:

a plurality of first filter arrays, each of the first filter arrays having a plurality of first filter patterns separated from each other;

a plurality of second filter arrays, each having a plurality of second filter patterns separated from each other; and

and each first filter array is adjacent to one of the second filter arrays and one of the third filter arrays.

2. The color filter array of claim 1, wherein each of the first filter array, the second filter array and the third filter array is rectangular in a top view.

3. The color filter array of claim 2, wherein each of the first filter arrays is adjacent to and substantially aligned with one of the second filter arrays and one of the third filter arrays along a length direction thereof, and each of the first filter arrays is adjacent to and substantially aligned with the other of the second filter arrays and the other of the third filter arrays along a width direction thereof.

4. The color filter array of claim 2, wherein each of the first filter arrays is offset from the one of the second filter arrays and the one of the third filter arrays along a width direction or a length direction of the first filter array.

5. The color filter array of claim 1, wherein a ratio of a length to a width of each of the first filter arrays is between 1.8: 1 and 5: 1.

6. The color filter array of claim 1, wherein a ratio of a width of each of the first filter arrays to a width of each of the first filter patterns is between 2: 1 and 5: 1.

7. The color filter array of claim 1, wherein a ratio of a width of each of the first filter patterns to a pitch of two adjacent first filter patterns is between 1: 1 and 3: 1.

8. A color filter array for a reflective display device, comprising:

a plurality of first filtering units;

a plurality of second filtering units; and

and each first light filtering unit is adjacent to one of the second light filtering units and one of the third light filtering units along a first direction, one of the first light filtering units is adjacent to the other of the second light filtering units and the other of the third light filtering units along a second direction and is arranged in a staggered manner, and the first direction is vertical to the second direction.

9. The color filter array of claim 8, wherein each of the first filter units, each of the second filter units, and each of the third filter units has a rectangular shape at an upward viewing angle.

10. The color filter array of claim 9, wherein the first direction is a length direction of each of the first filter units, and the second direction is a width direction of each of the first filter units.

11. The color filter array of claim 8, wherein a projection of the first filter unit along the second direction partially overlaps with the other of the second filter units.

12. The color filter array of claim 8, wherein an edge of the first filter unit and an edge of the other of the third filter units are aligned with each other along the second direction.

13. The color filter array of claim 8, wherein a ratio of a width of each of the first filter units to a length of each of the first filter units is greater than or equal to 1/3.